Electrooptic integrated optics spectrum analyzer: an experimental investigation

An integrated optics spectrum analyzer based on using the linear electrooptic effect was theoretically investigated earlier. This spectrum analyzer performs Fourier analysis of sampled electronic signals, where each voltage sample is fed to an electrode of a metal electrode array. The electrode array acts as a spatial light modulator, and the diffracted light field is focused on a detector array. The intensity values at the detector elements represent a weighted discrete Fourier transform of the voltage values on the electrodes. The first experimental results to verify the principle of operation of the device are now reported and compared with theory. The prism coupling technique has been used to investigate the influence of an electrode array with voltages on a collimated beam in a LiNbO(3) waveguide. The voltage distributions analyzed correspond to a square wave function and rect functions. The theory has also been extended, and some pertinent signal processing properties of the device are discussed.